Power system



March M, 1930.

OWER SYSTEM Filed OC'b. 20, 1927 39 rNvENToR 4 Naf/'ew H. (bnf/ee @ahmedil, 1930 UNITED STATES PATENT orrc'e.

NDREW H. CANDEE, OF 'WILKINSBURG, IPENNSYLVAX, ASSGN 'W-LISTTLNG- HOUSEELECTRIC & MANUFACTURING CMPANY, A CORPRATEON @E YENNSYL- VANIA 'POWERSYSTEM Application ined october 2o, i927. serial ne.. 227,448.

The invention relates to power systems utilizing.internal-combustionengines as prime movers and electric motors as work-performing units.

The object of the invention, generally stated, is the provision of apower system th at shall be simple and efficient in operation andreadily and economically manufactured.

A more specic object of the invention is to provide for operating thegenerator of a power system as a motor to start the engine.

Another object of the invention is to provide for utilizing thegenerator of a power system for charging the battery when the engine isidling.

A further object of the invention is to provide for closing. andinterrupting the charging circuit between the exciter ota power systemand the battery, according as the exciter voltage rises above or fallsbelow a predetermined value.

It is also an object of the invention to provide for operating theauxiliary motors, such, for example, as compressor motors, from the maingenerator of the power system when the engine is idling and 'from theexciter when the engine is loaded.

@ther objects of the invention will, in part, be obvious, and will, inpart, appear hereinafter.

The invention, accordingly, is disclosed in the accompanying drawingandcomprises the features of construction, combination of elements andarrangement of parts which will be exemplified in the constructionhereinafter set forth, and the scope of the a plication of which will heindicated in the c aims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description, taken inconnection with the single figure of the accompanying drawing, which isa diagrammatic showing of the power system sho'wing the preferredcircuit connections;

Referring now to the drawing, 'l0 designates, generally, aninternal-combustion engine of a type suitable to be utilized as theprime mover of a power system. In this particular instance, an engine,having an ignition system, 1s illustrated, but it 1s to be understoodthat an oil engine or'other variablespeed prime mover which may beoperated at low speed when the main load is removed, such, for example,as a Diesel engine, may be substituted.

As will be observed, a generator 11 and an auxiliary generator orexciter 12 are mounted on the engine shaft 13. As illustrated, thegenerator 11 is provided with a series ield winding 14, an interpole eldwinding 15 and a shunt ield winding 16, while the exciter 12 is providedwith a shunt field winding i7 and a series field Winding 18.

ln power "systems, particularly power systems utilized for propellingvehicles, it is often desirable to provide auxiliary motors foroperating auxiliary apparatus, such as compressors and the like. ln thisshowing ot the invention, only one auxiliary motor 19 is illustrated andhereinafter it will be referred to as the compressor motor.

lVhen the power system is utilized lor propelling a vehicle and thelike, two driving motors 20 and 21 are usually provided. The motors 2Oand 21, as illustrated, are ot the series type and disposed to beconnected in either series or parallel arrangement.

Since, in this particular embodiment of the invention, aninternal-combustion engine provided with an igition system isillustrated, the control means for the engine comprises a spark lever 22and a throttle lever 23. As will be readily understood, the spark levermay be disposed for controlling the ignition circuit and the throttlelever 23 for controlling the supply of fuel to the engine. rlheconnection of the spark lever 22 in they ignition circuit, and thethrottle lever 23 in the fuel circuit is not illustrated since suchdevices are well-known in the art and would only complicate the presentdiagram.

The remainder of the apparatus, such as the controllers 24 and 25, whichare normally mounted at opposite ends of the vehicle, and the reversingswitch 26. are well-known in the art and, therefore` will not bedescribed in detail, but their functions will become apparent as thedescription of the operation of the power system proceeds.

Assuming nowthat it is desired -to cause .the power system to function,the engine l() is for operating the generator 11 as a motor and theauxiliary apparatus when the engine is loaded. In order to connect thegenerator 11 across the battery 27, the spark lever 22 is thrown to itsstart position and the throttle lever 23 to its idling position,actuating the switches 28 and 29, respectively, to their lowermostpositions.

As will be observed, actuating circuits for the switches 30 to 32,inclusive, are now established. The actuating circuit for the switch 30may be traced from the battery 27 through conductors 33, 34 and 35, theinterlock 36 on the switch 28, conductors 37 and 38, the actuating coilof switch 30, conductor 39, 40 and 41, back to the battery, while theactuating circuit for the switch 31 may be traced ,from the energizedconductor 37, through the actuating coil of the switch, conductors 42,40 and 41, back to the battery. The actuating circuit for the switch 32extends` from the energized conductor 35 through conductor 43, interlock44 on the switch 28, conductor 45, the emergency trip button 117, theactuating coil of switch 32, conductor 46, back to the negativelyenergized conductor 39.

Upon the closure of the-switches 30 to 32, inclusive, a circuit foroperating-the generator as a motor is established and may be tracedAfrom the battery 27, through conductor 33, switch 31, conductor 47, thearmature of the generator, the series field 14 of the,

generator, conductor 48, switch 30 and conductor 41, back to thebattery.

It will be readily understood that, as soon as the engine begins tooperate, it will drive the generator and ldeliver current to thebattery. The series field 14 serves to protect the battery against anexcessive flow of current.

Immediately after the engine starts, the spark lever 22 is thrown to itsrun position, actuating the switch 28 to its uppermost position.

The actuating circuits for the switches 30 to 32, inclusive, are changedby the operation of the switch 28, but these switches are held closed.The new actuating circuit for the switches 30 and 31 may be traced fromthe positively energized conductor 35, through conductor 43, theinterlock 49 on the switch 28, conductor 50, the interlock 51 on theswitch 32, conductor 52, the interlock 53 on the switch 29, conductor54, to the conductor 37, from whence theactuating circuits lof theswitches arethe same as hereinbefore traced.

It will also be noted that the conductor 52 is connected to theconductor 45 so that the latter is positively energized when the switch28 is actuated to its uppermost position. Therefore, the actuatin'circuit for the switch 32, as traced throug the conductor 45, ismaintained.

Since this power system was primarily intended to be utilized inpropelling vehicles, provision is made for operating auxiliaryapparatus, such as compressors and the like, (not shown). In order toillustrate the manner in which such auxiliary apparatus may be operated,a compressor motor 19, hereinbefore referred to, is shown connected inthe circuit.

In a power system of this kind, in the interest of efliciency, it isdesirable to operate the compressor motor 19 from the generator when theengine is running substantially without load, which is generallydescribed by saying that the engine is idling. In some cases, it isundesirable to operate the auxiliary apparatus continuously, as in thecase of a compressor. Accordingly, means is provided for automaticallyconnecting and disconnecting the auxiliary apparatus to the generatorwhen it is desired to operate it. In this particular power system,provision is made for connecting the compressor motor to the generatorwhen the air pressure in the reservoir, (not shown) which is provided onall railway vehicles, falls below a predetermined amount an'd operatesthe governor switch 55.

Assuming now that the governor switch 55 is closed, an actuating circuitfor lthe switch is established which extends from the positivelyenergized conductor 35, through conductor 43, interlock 56 of the switch28, conductor 57, the interlock 58 on the switch 29, conductor 59, theactuating coil of the compressor motor switch 60, conductor 6l andgovernor switch 55, to the negatively energized conductor 41.

Upon the closure of the switch 60, the compressor motor is connectedacross the generator 11, the circuit extending from the armature of thegenerator 11, conductor 62, switch 60, conductor 63, the motor 19,conductors 64, and 33, switch 31 and conductor 47, back to thegenerator.

The compressor-motor circuit will be interrupted upon the actuation ofthe compressor governor switch 55 to its open position upon the pressureinthe reservoir reaching a predetermined value.

In order that the generator may be utilized for operating the compressormotor 19, charg, ing the battery 27 and supplying a lighting circuitwhen idling, provision is made for energizing its field windings. Inthis instance, be ore the charging process is started, the generatorshunt field 16 is connected across the battery, and an ener izingcircuit is established which extends om the battery 27, throughconductor 65, resistor 71, field winding 16, conductors 118 and 119, ex-

citer iield 18, conductors 84C, 40 and All, to the negative terminal oithe bfrttinyc lllhen the generator voltage reaches a value greater thebattery Voltage, and the charging Jprocess begins, the energizingcircuit itor the field Winding 'i6 will Vbe the saine as traced tronithe battery, 'with the exception that it 'will have'its origin at thepositively ener gized conductor 166.

lt will be noted that the lighting systeni of the Vehicle, which isdiagrarninatically illustrated by lamps 66, is directly connected acrossthe battery and, when the engine is idling, the generator' output isdivided between the charging ot the battery and the `lauro load. Whenthe engine is loaded, the

light circuit is supplied by the exciter.

ltlhen it is desired to load the engine to inove the vehicle or do someother Work, 'the throttle lever 23 is thrown to its run position,actuating the switch 29 to its upperinost position, interrupting theactuating circuits for the switches 30. 3l and 60. llurther, anactuating circuit for the switch GO cannot be established as long as thethrottle lever 23 remains in its run positions., rlhereg tore, thecompressor inotor cannot be connected to the generator il when theengine is loaded l "Ehe actuation oi the switch 29 to its uppermostposition establishes a new actuating circuit for the switch 32 Whichentends 'troni the positively energized conductor 35 through conductor43, the interlock 49 on the switch 28, conductor 50, interlock 5l oi"-the switch 32, conductors 52 and 45, the actuating coil of the switch 32and conductor 556, back the negatively energized conductor Therefore,when the throttle lever is thrown to its run position, the switch 32 isretained closed.

llVhen it is desired to load the engine 'l0 and the generator ll,provision is rnade 'for energizing the held windings oi' the generator'il and the exciter l2 As will benoted, the

'exciter shunt field 17 is connected directly across the battery 27, thecircuit extending from the positive terminal ot the battery throughconductors 33 and 65, switch 32, conductor 37, variable resistor 63,nel-d Winding i7, conductors 69 and llt), field Winding 13 andconductors 34:, 40 and lil, bach to the battery. The energizing circuitfor the shunt iield Winding lo oit the generator entends troni thepositively energized conductor 65, through switch 32, conductor 70,resistor 7l, which, as illustrated, is divided into sections, shunttield Winding 16 and conductors liti, 119, tield 'Winding 18, conductors34, l0 and 4l, bach to the battery 27 ln order to operate the compressorrnotor 19 when the engine is loaded,` provision is made lor connectingit to the exciter 13. The

tion of the compressor motor i9, as hereerplained, Will depend upongovernor switch 55. Assuming that thegovernor switch is closed, anactuating circuit or the switch 7 2 will be established from thepositively energized conductor 35, through conductor 4&3, the interlock56 on the switch 23, conductor 73, interlock l on the switch 29,conductor 75, interlock 7 6 on the switch 29, conductor 77, theactuating coil oic switch 72, conductor 6l, the governor switch 55 and,through the conductors l0 and 41, back to the batteryu Upon the closureot switch 7 2, a motor cir-- cuit is blished 'which entends :troni theexciter l2, throughconductors 73, 65 and 64, motor 19, switch 72 andconductor 73, back to the exciter.

lllith aV View to charging the battery when the engine and generator areoperating under load, provision is inode. for connecting it to theexciter when the voltage oiC the latter has reached predetermined value.The er.- citer-battery-chargii circuit is controlled by a diilerentialrelay, shown generally at 80. Assuming now that the exciter voltagereaches a predetermined value suiiicient the charging operation, thevoltage coil 3l oi the relay, which is connected across the egtn citer,is sufficiently energized to actuate the relay., The exciting circuitfor the Volt* ye coil 3l entends troni the exciter, ductor 32, coil 3iand conductors 33 and through con- '/Q u u, e exciterB 1 ,L LY 1 l .E oenoted tnat, upon the closure or established which er;m

bach: to

Withe relay 30, a circuit is tends troni the exciter l2, throughconductors 7 3, 35 and 33, battery 27, conductors Lil, i0 and 3st,series iield i3, the relay 30, the current coil ot the differentialrelay, conductors 33 and 79, bach the excitern lit, -tor any reason, thespeed of the engine is decreased, so' that the Voltage ot the E thebattery, it is desirciter is less than that oi able the relay 30 shouldfunction and in terrupt the charging circuit. l/l hen the 'volt ageoithe exciter is less than that ot the hattery, current i'lows troni thebattery through conductors 33, 65 and 73, the armature ot the exciterl2, conductors 79 and 33', the current coil 35 of the relay 3U, theinterlock 3G ot the relay, the series field i8, conduct-ors St, l0 andlll, bach to the battery. The action oi the current coil 35 being nolonger cumulative with that oi the 'voltage coil 3l, they neutralize oneanother and permit therelay to open under the action ot gravity. ln suchmanner, the charging circuit is interrupted when the exciter Voltagebecomes less than the battery voltage.

As pointed out hereinbetore, the lighting circuit is connected acrossthe battery and, when the exciter is connected across the hattery tocharge it, the exciter output is divided,

art being used 'or illuminating purposes and port for charging thebattery.

Since the operation oi a plurality ot motors' switch 87, conductor.series relation, one of the controllers,

'in series and in parallel relation from a generator is well-known, onlya general description will be given. Assuming that it is desired tooperate the motors 20 and 21 in say controller 24, is thrown to itsforward position, and the switch 87 to its series position, establishinga circuit extending from the energized conductor 73, through conductor88, contact member 89 on the controller 24, conductors 90 and 91, theactuating coil 92 of the reversin switch 26, through the negativelyenergize conductor 39. Further, an actuating circuit for theseries-relay switch 93 is established which may be traced from thepositively energized conductor 91, through the contact segment 94 of thereversing switch 26, conductors 95 and 96, the actuating coil of theswitch 93, conductor 97, interlock 98 on the relay switch 99, conductors100 and 101, the contact segment 102 of the series-parallel 103, contactsegment 104 on the controller 24 and conductor 105, back to thenegatively energized conductor 39.

A motor-operating circuit is now estab?- lished which extends from thegenerator 11, through conductors 47, 106 and 107, the armature of motor20, reversing switch 108, the series field of motor 20 reversing switch108, conductors 109, 110, the series switch 93, conductor 111, thearmature of motor 21, the reversing switch 112, the series field of themotor 21, reversing switch 112, conductor 113 and the interpole fieldwinding 15, back to the generator. V

It will be readily understood that, by throwing the switch 87 to itsarallel position, which is the one illustrated) in the drawing, therelay switches 99 and 114 may be operated to establish parallel-circuitrelations between the motors 20 and 21.

In power systems of this kind, particularly when they are applied tovehicles, it is desirable to provide for limiting the generator torquein order to prevent the possibility of stalling the engine by applyingan excessive load. In order to accomplish this, a torque governorsimilar to the one disclosed in copending applications, Serial Nos.227,459 and 227,460, filed in the name of Norman W. Storer and assignedto the Westinghouse Electric and Manufacturing Company, is utilized. Asillustrated, the rotor Winding 115 of the tor ue overnor is connectedacross the interpole el 15, while the field winding 116 is connected inseries with the shunt field 16 of the generator and across a section ofthe resistor 71. The switch member 120, disposed to be actuated by thegovernor, is connected to short-circuit a section oaf the resistor 71 tocontrol the energization of the generator shunt field winding, in amanner set forth in the applications hereinbefore referred to.

Since numerous changes may be made in the above described power systemand different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all mattercontained inthe above description or shown in the accompanying drawingshall be interpreted as illustrative and not in a limiting sense.A

I claim as my invention:

1. In a power system, in combination, an internalcombustion engine, agenerator driven by the engine, a battery disposed to be connected tothe generator, and means disposed to control the connections between thegenerator and battery to provide for the charging of the battery whenthe engine is idling and for disconnecting the battery from thegenerator when the engine carries a load.

2. In a power system, in combination, an internalcombustion engine, agenerator driven by the engine, a battery disposed to .be connectedacross the generator, means for connecting the generator to the batteryto operate it as a motor for starting the engine, said connecting meansbeing adapted to maintain the battery-generator connections when theengine is idling, and means for interrupting the charging circuit whenthe enginel is loaded.

3. In a power system, in combination, a generator, a battery, acompressor motor disposed to be connected to the generator, saidcompressor motor being disposed to be connected across the battery, andmeans for effecting the different connections of the compressor motor.

4. In a power system, in combination, a compressor motor, sources ofpower comprising a generator and a batter each capable of operatin thecompressor motor, and control means or the power system operable toconnect the compressor motor to the generator and battery, and totransfer the con-l nections from one source other.

5. In a4 power system, in combination, an internal-combustion engine,means for controlling the operation of the engine, a generator driven bythe engine, a compressor motor dis osed to be connected to thegenerator, a attery capable of operating the compressor motor, means forconnecting the compressor motor to the generator and battery, saidconnecting means being responof power to the sive to the operation ofthe engine-control 1 means.

6. In a power system, in combination, aninternal-combustion engine,means for controlling the operation of the engine, said control meanshaving idling and run positions, a generator driven by the engine, a

compressor motor disposed to be connected to the enerator, a batterycapable of operatingt e compressor motor, means operable by said enginecontrol means for connecting 1' actuated by said engine control meansfor connecting the battery to the generator, said connecting means being.disposed 'for operation by the engine control means to interrupt thebattery-generator connections when the engine is loaded.

V8. InV a power system, in combination, a variable speed engine, a maingenerator and an auxiliary enerator driven by the engine, a plurality o?auxiliary circuits disposed to to be connected to the generators andmeans responsive to the loading of the engine for selectively connectingthe battery to the generators.

9. In a power system, in combination, a

variable-speed en ne, a generator and ex citer driven by t e engine, aplurality of auxiliary circuits, means for controlling the loading ofthe engine, and means responsive to the actuation of the loadcontrolling means for selectively connecting the auxiliary circuits tothe generator andexciter. i

10. In a power system, in combination, an engine adapted to be operatedat different speeds, a generator driven by the engine, said generatordeveloping a predetermined voltage when the engine is idling and adifferent voltage when the engine .is loaded, an exciter for energizingthe generator Iield windings, a..

lurality of auxiliary circuits to be supplied y the generator andexciter, and means responsi-ve to the loading of the engine forselectively connecting the auxiliary circuits to the generator andexciter.

11. In a. power system, in combination, an engine adapted to be operatedat an idling speed and under load, a generator and exciter driven b theengine, said generator and exciter eac being provided with di'erentialand series field windin s, auxiliary circuits dis osed to be connecte tothe generator and exciter, means for controlling the loading of the enne and means responsive to the loading o the engine for selectivelyconnecting the a xiliary circuits to the generator and exciter, saiddifferential and series eld windings of the generator and exciter'beingutilized to control the voltage supplied to the auxiliary circuits.v

12. In a power system, in combination, an engine adapted `to be operatedat an idling s eed and under load, a generator provide with differentialand series eld windings driven by the generator and capable of de- .agewhen veloping substantially constant voltages when thel engine operatesat its idling speed or under load, an exciter provided with differentialand series fieldwindings for energizing the generator ield windings,said gen# erator being driven by the engine and adapted to d evelop asubstantially constant voltthe engine is loaded and abattery providinganother source of constant voltage supply, said battery being disposedto be selectively connectedA to the generator and exciter.

13. Ina power system, in combination, an internal-combustion engineadapted to be operated at an idling speed and at a different Speed underload, sources of subtantially constant voltage comprising a generatorand an exciter driven by the engine and adapted to develop differentpredetermined voltages when the engine is idling and o erating underload, and means for control ing the voltages delivered, to maintain themsubstantially constant for the conditions of the engine, the batteryproviding another source of constant' voltage, a plurality of circuits,and means responsive to the loading of the engine for selectlvelyconnecting the circuits across the sources of substantially constantvoltage. In testimony whereof, I scribed my name this 45th day ofOctober,

ANDREW' H. CANDEE.

different operating v have hereunto sub-

